JEE Main Physics - Properties of Matter
Exam Duration: 60 Mins Total Questions : 30
A bolloon floating in air is given a slight lateral horizontal displacement. The baloon shall now be
- (a)
in stable equilibrium
- (b)
in unstable equilibrium
- (c)
in neutral equilibrium
- (d)
oscillating
Two steel wires have their lengths and diameters in the ratio of 1 : 2. Their elongation for the same stretching force will be in the ratio
- (a)
1 : 4
- (b)
4 : 1
- (c)
1 : 2
- (d)
2 : 1
Two rods A and B of the same material have both lengths and diameters in the ratio 2:1 respectively. They are subjected to equal torsional couples. If \(\tau _{B}\) are modulus of torsion
- (a)
1 : 4
- (b)
8 : 1
- (c)
1 : 8
- (d)
1 : 1
Choose correct statement :
- (a)
Metals have high young modulus and low elastic strain
- (b)
Glass has young modulus and low elastic strain
- (c)
Plastics are less stiff and do not obey Hooke's law like metals do
- (d)
All of the above
A liquid tank falls freely to the fround from a height of 30 m. The pressure at a point 2 m from the original water surface shall be
- (a)
less than atmospheric pressure
- (b)
greater than the atmospheric pressure
- (c)
equal to atmospheric pressure
- (d)
increasing continuosly
A ship,floating in clear water of density 1000 kg m-3 moves to sea-water of density1050 kg m-3 where it floats again.The upthrust on the ship then
- (a)
increases by 0.05 times
- (b)
decreases by 0.05 times
- (c)
stays constant
- (d)
first increases and then stays constant
A body of mass 0.8 kg flots partially in water.When another weight 0.2 kg is places over it,it just dips inside water.Its specific gravity is
- (a)
0.8
- (b)
1.0
- (c)
0.25
- (d)
1.33
A metre stick of a certain material floats in water with 20 cm above water level.When it floats in a liquid of specific gravity 0.8,how much of its length will be out of the liquid?
- (a)
nil
- (b)
25 cm
- (c)
64 cm
- (d)
4 cm
A liquid of specific gravity of 0.8 flows with a velocity of 4.42 ms-1.Its velocity head is
- (a)
0.8 m
- (b)
1 m
- (c)
1 ms-1
- (d)
19.62 m
A capillary tube of 2 mm diameter is immersed in a beaker containing mercury.The surface tension of mercury is 0.050 Nm-1 and its specific gravity is 13.6.The depression of mercury level in the capillary tube will be observed at
- (a)
7.35 mm
- (b)
7.02 mm
- (c)
7.35 x 10-3 mm
- (d)
7.18 mm
laminar flow is independent of
A.nature of surface in contact
B.pressure of flow
C.velocity of flow
- (a)
if A is correct
- (b)
if A,B are correct
- (c)
if B,C are correct
- (d)
if A,B,C are correct
When the temperature of a perfect gas increases
- (a)
the intermolecular attraction decreases
- (b)
the intermolecular attraction remains constant
- (c)
the intermolecular attraction is zero
- (d)
the molecules move far apart
The compressibility is minimum for
- (a)
water
- (b)
glycerine
- (c)
mercury
- (d)
ether
One end of a uniform wire of length L and of weight W is attached rigidly to a point in the ceiling and weight W1 is suspended at its lower end.If S is its area of cross-section,the stress in the wire at a height \(\frac{3L}{4}\)from its lower end is
- (a)
\(\frac{W_1}{S}\)
- (b)
\((W_1+\frac{W}{4})\frac{1}{S}\)
- (c)
\((W_1+\frac{3W}{4})\frac{1}{S}\)
- (d)
\((\frac{W_1+W}{S})\)
The compressibility of water is 4 x 10-5 (atmosphere).The decrease in volume of 100 c.c.of water under a pressure of 100 atmosphere will be
- (a)
0.4 c.c.
- (b)
4 x 10-5 c.c.
- (c)
0.025 c.c.
- (d)
0.004 c.c.
The substance which shows practically no elastically after effect is
- (a)
quartz
- (b)
copper
- (c)
silver
- (d)
rubber
Two rods A and B of the same material and length have their radii r1 and r2.If they are rigidly fixed at on end and twisted at other end by the same couple,then the ratio of their angles of twist is
- (a)
\(\frac{r_1^2}{r_2^2}\)
- (b)
\(\frac{r_1^3}{r_2^3}\)
- (c)
\(\frac{r_1^4}{r_2^4}\)
- (d)
\(\frac{r_2^4}{r_1^4}\)
The value of Poisson's ratio theoretically lies between
- (a)
-1 to 0.5
- (b)
-0.75 to -0.5
- (c)
-0.5 to 1
- (d)
1 to 2
Four maximum extension with given load for a given wire and same value of tension,which is true?
- (a)
Length = 100 cm,Diameter = 1 mm
- (b)
Length = 50 cm,Diameter = 0.5 mm
- (c)
Length = 200 cm,Diameter = 2 mm
- (d)
Length = 300 cm,Diameter = 3 mm
A hollow cylindrical mass m made heavy at its bottom is floating vertically in water.It is titled from its vertical position through an angle \(\theta\) and is left.The restoreing force acting on it is
- (a)
\(mg[1-\frac{1}{cos\ \theta}]\)
- (b)
\(mg[\frac{1}{cos\ \theta}-1]\)
- (c)
\(mg\ cos\ \theta\)
- (d)
\(\frac{mg}{cos\ \theta}\)
Two cylinders of same cross-section and length L,but made of two materials of densities p1 and p2(in cgs units) are cemented together to form a cylinder of length 2L.If the combination floats in water with a length L/2 above the surface of water and p1 < p2,then
- (a)
p1 > 1
- (b)
p1 > \(\frac{3}{4}\)
- (c)
p1 < \(\frac{1}{2}\)
- (d)
p1 < \(\frac{3}{4}\)
A piece of steel floats in mercury.The specific gravity of mercury and steel are 13.6 and 7.8 respectively.For covering the whole piece some water is filled above mercury.What part of the piece is inside the mercury?
- (a)
0.54
- (b)
0.50
- (c)
0.47
- (d)
0.62
Work of 3.0 x 10-4 J is required to be done in increasing the size of a soap film from (10 cm x 6 cm) to (10 cm x 11 cm).The surface tension of the film is
- (a)
5 x 10-2 Nm-1
- (b)
3 x 10-2 Nm-1
- (c)
1.5 x 10-2 Nm-1
- (d)
1.2 x 10-2 Nm-1
A soap bubble in vacuum has a radius of r1 and another soap bubble in vacuum has a radius of r2.If two bubbles coalesce under isothermal conditions then the radius of the new bubble is
- (a)
R = r1 + r2
- (b)
R = r1 - r2
- (c)
\(R = \sqrt {r_1^2 + r_2^2}\)
- (d)
\(R = \sqrt {r_1^2 - r_2^2}\)
A glass rod is dipped in mercury and withdrawn out,the mercury does not wet the rod because
- (a)
angle of contact is acute
- (b)
cohesion force is more
- (c)
adhesion force is more
- (d)
density of mercury is more
Two pieces of glass plate one upon the other with a little water in between them cannot be seperated easily because of
- (a)
vacuum in between them
- (b)
atmospheric pressure acting on the plates
- (c)
surface tension
- (d)
viscosity of water
If Cs be the velocity sound in air and C be the r.m.s. speed,then
- (a)
Cs < C
- (b)
Cs = C
- (c)
\(C_s = C \times\ \sqrt\frac{\gamma}{3}\)
- (d)
None of these
The average translational kinetic energy of O2(molar mass 32) molecules at a particular temperature is 0.048 eV.The translational kinetic energy of N2(molar mass 28) molecules in eV at the same temperature is
- (a)
0.0015
- (b)
0.003
- (c)
0.048
- (d)
0.768
Oxygen and hydrogen are at the same temperature.The ratio of the mean kinetic energy of oxygen molecules to that of the hydrogen molecules is
- (a)
16 : 1
- (b)
4 : 1
- (c)
1 : 1
- (d)
1 : 4